I can see why Census doesn't recommend do more than three variables at a time. When you add 17 counties together, you get a much bigger area with more households sampled. In theory, you should get a smaller MOEs compared each individual county. But if you derive MOEs from those 17 counties, you will get a much bigger MOEs, which is contradictory to the theory. ________________________________________ From: ctpp-news-bounces(a)chrispy.net [ctpp-news-bounces(a)chrispy.net] on behalf of Ed Christopher [edc(a)berwyned.com] Sent: Tuesday, March 12, 2013 11:15 AM To: ctpp-news(a)chrispy.net Subject: Re: [CTPP] Working with County flow data Thanks--I know the spread sheet allows you to recalculate MOEs for more than three variables but I remember doing more than 3 a while back and I was getting some wild MOEs. When I dug into it I found something in the Census compass reports that said not to do more than three variables at a time. I was hoping that someone figured out a way around this. Ed C On Mar 12, 2013, at 9:59 AM, "Hoctor Mulmat, Darlanne" <Darlanne.Mulmat(a)sandag.org<mailto:Darlanne.Mulmat(a)sandag.org>> wrote: The New York State Data Center developed a Statistical Calculations Menu that includes an option for computing the margin of error for the sum of three or more estimates. See attached. Darlanne Hoctor Mulmat Applied Research Division – Criminal Justice/Public Policy San Diego Association of Governments 619-699-7326 From: ctpp-news-bounces(a)chrispy.net<mailto:ctpp-news-bounces(a)chrispy.net> [mailto:ctpp-news-bounces(a)chrispy.net] On Behalf Of Ed.Christopher(a)dot.gov<mailto:Ed.Christopher(a)dot.gov> Sent: Tuesday, March 12, 2013 6:57 AM To: ctpp-news(a)chrispy.net<mailto:ctpp-news(a)chrispy.net> Subject: [CTPP] Working with County flow data Has anyone come up with some easy ways for collapsing and grouping counties together using last week’s county flow data and recalculating new MOEs. I have so many counties that I want to group together that I am looking for a quick way that can handle “lots” of counties. Another issue I am struggling with is that we are always told not to group more than three variables at a time or the formulas for calculating the new MOE do not really work. This is particularly troublesome especially if I am trying to group 17 counties together. What it comes down to is 9 different calculations given that I can only group 3 counties at a time together. Anyone figure out any short cuts or ways around this short of disregarding the MOEs altogether? Given all the clustering that I am looking at using the “cheat” sheets I am used to, I will be recalculating MOEs for weeks. Ed Christopher <StatisticalCalculationsMenu.xls> _______________________________________________ ctpp-news mailing list ctpp-news(a)ryoko.chrispy.net<mailto:ctpp-news(a)ryoko.chrispy.net> http://ryoko.chrispy.net/mailman/listinfo/ctpp-news